This invention relates generally to valve operating mechanisms for use in internal combustion engines and, more particularly, to an oscillating rocker arm assembly and subassembly having rolling members.
Typically, a rocker arm assembly with rolling members is supported on a support shaft mounted perpendicularly on a support stud extending from the head of the engine. The rocker arm is pivoted on the support shaft, which serves as an inner raceway, by means of drawn cup needle roller bearings mounted on the rocker arm. Alternatively, a bearing sleeve may be mounted on the support shaft to provide the inner raceway, permitting use of a non-cylindrical support arm and facilitating the use of powder metal forming.
In some applications of such rocker arm assemblies, there is a need to provide greater axial stability of the rolling members, that is, to limit movement of the rolling members to eliminate overhang of the rolling members with respect to the raceway and to provide support along the full roller length. Also, in some applications there may be a desire to limit axial movement of the rocker arm with respect to the support shaft without requiring contact of the roller ends with a flange of the bearing sleeve or similar stop surface.
The foregoing illustrates limitations known to exist in present rocker arm bearing assemblies. Thus, it is apparent that it would be advantageous to provide an alternative directed to overcoming one or more of the limitations set forth above. Accordingly, a suitable alternative is provided including features more fully disclosed hereinafter.